We are currently investigating the relation between the light stimulus incident on the human eye and the visual signals generated by the receptors, and the neural transformations these signals undergo as they are transmitted through the retina. Particular projects include: (1) Studies of lateral interactions in the control of sensitivity. Under this heading are three projects: (a) estimation of the size of cone receptor signals generated by strong lights, (b) at what stage of retinal processing the chromatic opponency which underlies color perception is first established and (c) the role of lateral interactions in the regulation of temporal sensitivity. (2) Anomalies in the perception of size of stimuli visible only to the blue-sensitive receptors. We are also investigating afterimage phenomena which may relate to questions of stability of the visual world and the nature of the representation of visual space.